The famed Peruvian chef Gastón Acurio said that ají amarillo is the most important ingredient in Peruvian cooking. Ají amarillo is a pepper paste made from capsicum baccatum peppers which flourish along the Peruvian coast and in Andean valleys. The whole fresh peppers are widely available in Peru, but home cooks typically purchase pre-made pastes which are in every grocery store and market in the country. In the United States, these pastes are available in many Latin markets, but there are also these ordering options on-line: